There are many applications where particulates are required to be separated from or detected in a liquid medium. For example, it is important to be able to detect and potentially remove particulates from water to allow water quality monitoring and treatment, or to allow the efficient removal or purification of cells within a medium, such as culture medium, or a bodily fluid such as blood.
The processing of liquid to remove or to detect particulate contaminants is of especial importance for detecting and/or removing water borne pathogens, such as Cryptosporidium or Giardia, for example, in and/or from water supplies. Other examples include the separation of cells from a medium, such as cell culture or a bodily fluid such as blood, for example.
Microfluidic devices are used to process small volumes of liquid (between 15 μl/min and 5 ml/min)1,2 and typically comprise a detector, such as a biosensor, for example. Accordingly, such devices are able to successfully detect very small concentrations of particulates or other contaminants. However, detection of biological species, for example, require small concentrated samples, and therefore, the use of biosensor devices and other detection devices for environmental monitoring are often limited by the low volumetric throughput and the time required to process a statistically relevant sample of treated water being too long for real world application.
Highly parallelised arrays of microfluidic devices3-5 allow a higher volume of liquid to be processed in a given timescale, or to carry out pre-processing of samples to concentrate and/or enrich samples to be tested. However, such arrays typically greatly increase the footprint and cost of the device, which in turn limits the applicability of such devices.
Therefore, there remains a need for a device that allows a high throughput of liquid to be processed in a realistic timescale that is cost effective and has a small footprint.
Typically, devices employ a form of filtration of the liquid to be processed to allow the particulates to be detected or collected for analysis. However, over time, especially in cases where the volume of liquid to be processed is high, the filters used typically become clogged or blocked with particulates, and must be replaced before further volumes of liquid can be processed.
Accordingly, it is an object of the present invention to provide an improved device for processing of large volumes of fluid.